processGeneric only accepting lambda functions?

I dont know if that is expected behavior: but i guess not. processGeneric seems not to accept functions not wrapped in a lambda body...? For example numpy funcs give:

AttributeError: 'numpy._ArrayFunctionDispatcher' object has no attribute '__globals__'

example:

import saqc
import numpy as np
import pandas as pd
qc = saqc.SaQC(pd.Series([1], index=pd.DatetimeIndex(['2000']), name='dat')
qc.processGeneric('dat', func=np.sum)